20997506240 has 28 divisors (see below), whose sum is σ = 50000312496. Its totient is φ = 8399002368.

The previous prime is 20997506237. The next prime is 20997506267. The reversal of 20997506240 is 4260579902.

It is a junction number, because it is equal to n+sod(n) for n = 20997506191 and 20997506200.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32808284 + ... + 32808923.

Almost surely, 2^20997506240 is an apocalyptic number.

20997506240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20997506240 is an abundant number, since it is smaller than the sum of its proper divisors (29002806256).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20997506240 is an equidigital number, since it uses as much as digits as its factorization.

20997506240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65617224 (or 65617214 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 44.

The spelling of 20997506240 in words is "twenty billion, nine hundred ninety-seven million, five hundred six thousand, two hundred forty".